WASHINGTON - Some feisty Republicans are challenging a claim widely held among GOP leaders that the party must support more liberal immigration laws if it's to be more competitive in presidential elections.

These doubters say the Republican establishment has the political calculation backward. Immigration "reform," they say, will mean millions of new Democratic-leaning voters by granting citizenship to large numbers of Hispanic immigrants now living illegally in the United States.

The argument is dividing the party as it tries to reposition itself after losing the popular vote in five of the past six presidential elections. It also could endanger President Barack Obama's bid for a legacy-building rewrite of the nation's problematic immigration laws.

Many conservatives "are scared to death" that the Republican Party "is committing suicide, that we're going to end up legalizing 9 million automatic Democrat voters," radio host Rush Limbaugh recently told Sen. Marco Rubio, R-Fla., a leader of the bipartisan team pushing an immigration overhaul.

Strategists in both parties say several factors, including income levels, would make many, and probably most, newly enfranchised immigrants pro-Democratic, at least for a time.

Rubio says the risk is worth taking.

"Every political movement, conservatism included, depends on the ability to convince people that do not agree with you now to agree with you in the future," he told Limbaugh.

Politically, Republicans face two bad options.

They can try to improve relations with existing Latino voters by backing a plan that seems likely to add many Democratic-leaning voters in the years ahead. Or they can stick with a status quo in which their presidential nominees are losing badly among the electorate's fastest-growing segment.

In 2012, Republican presidential nominee Mitt Romney, who suggested that vanishing job opportunities would prompt immigrants to "self deport," carried only 27 percent of the Hispanic vote. A Republican Party study of that election concluded, among other things, that the GOP must appeal to more Hispanics, and to do so it must "embrace and champion comprehensive immigration reform."

Party leaders say the harsh language that some Republicans use when discussing illegal immigration has angered many Americans with Hispanic heritages.

Rubio's bipartisan group has proposed legislation to strengthen border security, allow tens of thousands of new high- and low-skilled workers into the country, require all employers to check their workers' legal status, and provide an eventual path to citizenship for some 11 million immigrants now in the country illegally.

Even if the bill survives the Democratic-controlled Senate, stiff resistance is expected in the GOP-dominated House. Many House Republicans dislike the idea of "amnesty" for those who crossed the border illegally, and some say it's foolish to enfranchise likely Democratic voters.

Obama embraces the Rubio plan, and it won crucial praise from House Speaker John Boehner, R-Ohio, and Rep. Paul Ryan, R-Wis., last year's vice presidential nominee.

Rubio and his allies challenge the notion that creating a way to citizenship for millions of people here illegally will dramatically increase Democratic turnout in future elections.

"Not all 11 million illegal immigrants here today will qualify to become citizens, and not all of the 11 million illegal immigrants are Hispanic," according to Rubio's "Myth vs. Fact" website. The site says many immigrants will not choose to become citizens, and many new citizens, like many current ones, will not bother to vote.

Some Republican campaign strategists, however, say the political damage would be worse than party leaders acknowledge.

Republican consultant and pollster Mike McKenna said one of his surveys shows that most Americans favor "immigration reform" and they believe it will benefit Democrats more than Republicans.

In an interview, McKenna said Republican leaders are embracing Rubio's plan without sufficient data on where it might lead. "I think about two months from now, the folks in the establishment are going to wish they hadn't started this conversation," McKenna said.

Party leaders erred, he said, by couching the immigration debate in political rather than moral terms. "The argument that it's going to be politically advantageous is not going to be sustainable over time," McKenna said.

Political activists have swapped estimates of how many people now living here illegally might choose to become citizens, register to vote and turn out for Democratic candidates if a path to citizenship is opened. Even the most conservative guesses assume that Democrats would benefit more than Republicans, initially, at least.

Rubio's allies play it down.

"The status quo is not acceptable to Republican voters," said GOP consultant Kevin Madden, who has worked for Romney and others. Republican leaders, he said, must push for the best rewrite of immigration laws they can achieve.

Texas-based GOP consultant Matt Mackowiak noted that evangelical leaders, major business groups and others that opposed immigration changes in 2007 are now on board. He said the Republican Party should focus on attracting Hispanic voters with its standard message of small government and free enterprise, and not worry too much if a new law produces more Democratic-leaning voters for a while.

"If we don't win 40 to 45 percent of Hispanics," Mackowiak said, "we're not going to win elections regardless of whether this happens."

Limbaugh is among those who don't buy it.

"I see polling data again that suggests that 70 percent of the Hispanic population in the country believes that government is the primary source of prosperity," he told Rubio in their recent exchange. "I don't, therefore, understand this contention that Hispanics are conservatives-in-waiting."